Gillette is located in Campbell County (of which it is the county seat) northeast of Casper between Buffalo and Sundance along Interstate 90 near Thunder Basin National Grassland.
The population estimate for July 1, 1998 was 19,463, an increase of 1,918 since 1990.
Edward Gillette, a railroad surveyor, found a shorter route for the railroad which saved 30 bridges and came by the present site of Gillette. For this service, the town of Gillette was named in honor of him. (Allowing the residants to change the name from "Donkey Town").